• Journal of Industrial Technology
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• v.21 no.B
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• pp.257-263
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• 2001

Terminal paging is the process of determining the exact location of a particular mobile terminal. The paging cost is related to the number of paging cycles and the number of cells being polled by each cycle. In this paper, we first analyze the performance of various terminal paging strategies in terms of the number of polling cycles and the number of polling signals. Then we present a paging scheme which combines Shortest-Distance-First with movement history list. Simulation results show that the proposed paging scheme reduces the number of polling signals as well as the number of polling cycles.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.5B
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• pp.457-465
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• 2003

In this paper, we analyze the performances of variable MAC (Medium Access Control) protocols and present an efficient MAC protocol for Ethernet PON (Passive Optical Network). We consider three MAC protocols: static TDMA, dynamic TDMA, and Interleaved polling. Static TDMA assigns an equal amount of bandwidth to all ONUs regardless of the request information but Dynamic TDMA dynamically allocates the bandwidth to each ONU considering its request. Interleaved Polling operates a cycle with variable time period and a polling method for informing a uplink transmission chance to each ONU. This paper theoretically analyzes the available bandwidth for each of three protocols. We also implement the simulation models for them by using OPNET and evaluates the performances under various bursty traffic environments. The results are compared and analyzed in terms of channel utilization and queueing delay.

• Journal of the Korean Operations Research and Management Science Society
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• v.17 no.1
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• pp.77-84
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• 1992

Queueing models with service can be applied in the area of performance studies of polling systems in data communication and switching systems. We provide a new approach for analysis on the cycle time of the multiqueue system consisting of statistically identical stations where at most one message is served for any station in a polling cycle. We assume an independent Posson arrival at each station. The message service time and switchover time are assumed to be constant. Based on the dependence between the stations, cycle time distribution is derived. Then, this result is validated by a computer simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.3B
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• pp.114-129
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• 2005

In this paper, we examine Interleaved Polling with Adaptive Cycle Time (IPACT) algorithm which was proposed to control upstream traffic for Gigabit Ethernet-PONs, and we analyze the performance of the gated service and the limited service of the IPACT mathematically. For the mathematical performance analysis, we model IPACT algorithm as a polling system and use mean-value analysis. We divide arrival rate λ value into three regions and analyze each region accordingly. We obtain average packet delay, average queue size and average cycle time of both the gated and the limited service. We compare analytical results with simulation to verify the accuracy of the mathematical analysis. Upon now, simulation analysis have been used to evaluate the performance of EPONs, which require much time sud effort. Mathematical analysis can be widely used in the design of EPON systems since system designers can obtain various performance results rapidly.

• Journal of Internet Computing and Services
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• v.8 no.4
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• pp.41-49
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• 2007

Ethernet passive optical network(EPON) is the next-generation technology for supporting services of high-quality at low-cost. In the EPON, all optical network units(ONUs) have to share a limited uplink channel for upstream data. In order to satisfy bandwidth demands of users on high-capacity local access networks(LANs), the optical line terminal(OLT) efficiently divides and allocates time slots of uplink channel to all ONUs. We discuss previous schemes for dynamic bandwidth allocation(DBA), such as interleaved polling with adaptive cycle time(IPACT) and sliding cycle time(SLICT). In this paper, dynamic right sizing of maximum-windows(DRSM), as a novel bandwidth allocation service, is proposed for more effective and efficient time slot allocation of the uplink channel. DRSM which is based on past information of bandwidth allocated by OLT calculates maximum available bandwidth and dynamically alters the maximum window size for the next ONU. This scheme does not only exert every effort to meet bandwidth demands of ONUs with the possible scope, it also seeks fairness of bandwidth allocation among ONUs.

• Journal of Korean Society of Transportation
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• v.22 no.6
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• pp.77-88
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• 2004

This study aims at developing the model that is able to detect the compression wave, which is included as a similar situation in incidents, that causes false applicable to the similar character such as incidents in the incident detection model for expressways. In this study, it has been checked whether the number of false alarms is decreased or not by modularizing this model for being able to applicable to other models such as DES and DELOS, etc. which do not perform the compression wave test based on the compression wave test process of APID model which has been being used in the expressway traffic management system currently. The evaluation in this study focuses on the sensitivity of the model and the results analysis is performed classified by each polling cycle. And how well these models are working is evaluated by each polling cycle. In addition to this, the detection rate, the false alarm rate and the average detection time in both the existing models and the model in this study are calcuated. As a result of appling the model in this study, it is found that the false alarm rate is improved through the reasonable decrease in the number of false alarm frequencies and there are not remarkable changes concerning the detection rate and the average detection time. To sum up, it is expected that a good number of improvement effects will be occurred when this model is applied to the actual expressway traffic management system.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.7
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• pp.31-40
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• 2004

In this paper, we analyze mathematically the performance of the gated service scheduling in the Interleaved Polling with Adaptive Cycle Time(IPACT) was proposed to control upstream traffic for Gigabit Ethernet-PONs. In the analysis, we model EPON MAC protocol as a polling system and use mean value analysis. We divide arrival rate λ into three regions and analyze each region accordingly In the first region in which λ value is very small, there are very few ONUs' data to be transmitted. In the second region in which λ has reasonably large value, ONUs have enough data for continuous transmission. In the third region, ONUs' buffers are always saturated with data since λ value is very large. We obtain average packet delay, average Queue size, average cycle time of the gated service. We compare analysis results with simulation to verify the accuracy of the mathematical analysis. Simulation requires much time and effort to evaluate the performance of EPONs. On the other hand, mathematical analysis can be widely used in the design of EPON systems because system designers can obtain various performance results rapidly. We can design appropriate EPON systems for varioustraffic property by adjusting control parameters.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.635-637
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• 2016

센서 네트워크에서 각 센서 노드의 에너지 소모를 최소화하여 에너지 소모를 줄임으로써 망의 지속시간을 늘이는 것이 중요하다. 기존의 MAC(Medium Access Control) 프로토콜은 채널 폴링 기법을 이용하여 효율적인 에너지 관리에 대한 해결책을 제시 하였으나, 그러한 방식에 따른 각 노드의 Duty Cycle이 길어짐으로써 발생하는 에너지 소모에 대한 해결책은 제시하지 못하였다. 본 논문에서는 기존의 채널 폴링과 함께 스케쥴링 알고리즘을 적용하여 Duty Cycle의 주기를 줄임으로써 에너지 소모를 줄인다. 특히 이 방식을 이용하여 멀티홉과 과다한 트래픽에 대한 성능의 평가를 위해 실험을 통해 제안하는 프로토콜의 우수한 성능을 보인다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.8
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• pp.45-53
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• 2004

This paper proposes and analyzes a new media access control (MAC) scheduling algorithm, “Interleaved Polling with Deficit Round Robin (IPDRR)” that supports weighted fairness among ONUs in Ethernet Passive Optical Network (PON). The purpose of the proposed IPDRR algerian is not only to eliminate the unused bandwidth of upstream ONU traffic, but also to provide weighted fair sharing of upstream bandwidth among ONUs in Ethernet PON systems. Simulation results show that the IPDRR improves the utilization of upstream channel by removing the unused bandwidth and provides weighted fairness among ONUs, although the IPACT scheduling is unfair according to traffic characteristics.

• Korean Journal of Applied Biomechanics
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• v.22 no.1
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• pp.95-104
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• 2012

The purpose of this study targeted to national cross-country skiers representatives was to implement hypothetical experiment on their patterns of the movements and analysis on kinematic variables occurred while double polling was conducted between starting and finishing phase of 56 meters. Furthermore, it aimed to provide a set of quantitative data to illustrate how to improve one's skill and performance of sprint. In our experiments, we conducted 3-dimension analysis of cycle characteristics, joint angle(hip, knee and elbow), and pole angle. The results showed that at the starting phase, the players did not show a significant difference in attributes of time and distance. In heat 1 where elbow angle and polling starts, the pole angle was noticeably high in heat 1. At the finishing phase, there was a considerable distinction with a high frequency in performing a short polling time and high speed in heat 3. The players showed large extension between the flexion and of the hip angle which indicates high contribution given from the movement of lower body(hip, knee).